Notes of Ch 4 Introduction to HTML Computer| Class 9th

• Who Invented HTML: HTML was invented in November 1990 by a scientist called Tim Berneses-Lee.

• A brief history: HTML is an improved version of Standard Generalised Markup Language(SGML) which is a Meta Language used for defining and creating descriptive markup language.

• Tools needed to get started with HTML documents:

→ A text editor/HTML editor

→ A Web Browser

• Tags and attributes

→ A tag is a special word enclosed in angle-brackets < >. It tells the browser to perform an action as asked by the special word.

→ The characteristics or the features of a tag are defined by an attribute. An attribute is used
inside a tag which always takes a value to help the browser perform the specific task in a particular direction.

→ An element is a combination of a start tag, the text and the end tag.
For example: <body> element begins with start tag, followed by text and ends with end tag.</body>

• Container of Tags: One set of tags may contain another set of tags. This is called nesting
of tags. For example: <TAG1> <TAG2>……………</TAG2> </TAG1>.

Here, <TAG1> and </TAG1> is the first block of tags. <TAG2> and </TAG2> is the second block of tags.

Structure of HTML document

• Basic structure of HTML document is:

• The basic structure of the HTML document is divided into two sections namely, the head and the body.

→ The first section helps in changing the heading on the title bar of the HTML document (the webpage).

→ The second section begins with the start tag of BODY. The data on the webpage is displayed through the tags used in this section.

Saving the HTML document

• After writing HTML code, click on File menu and select Save option. A window open asking o save the file in a folder. Give a name and an extension to the file. The extension in this file will be .html or .htm. which will turn the file into a webpage.

• To modify the webpage, either open the web page and click on View →source or open the webpage with notepad.Container and empty tags

• A container tag has both the start and the end tag. The text or the graphic is inserted inside the beginning and end tag of the container tag. For example: <body>This is a container tag</body>. The <BODY> tag here is a container tag which has both the beginning and the ending tag and the text in between both the tags.

• The empty tag is a stand-alone tag. This implies that such a tag has beginning but no ending tag. For example: The <BR> tag is used for adding one line break.

→ Other empty tags are HR tag, Comment tag.BODY tag

• The second section of the webpage begins with the <BODY> tag. This defines the visible section of the document.

• It has a number of attributes which controls the overall appearance of the document. Below is the list of attributes of the <BODY> tag:

Formatting Elements • There are a number of tags that help you to format the text.

• <Heading tags>: It is used to display the heading or the main topic on the web page. This tag varies from H1 to H6.

→ This is a container tag.

→ The font size of headings decreases with the increase in the number of heading tag.

→ The <H1> tag shows the heading with the largest font size while <H6> tag shows the heading with the smallest font size.

• <FONT> tag: The FONT tag is a container tag that has a number of attributes given in the table.

• Entering Paragraph text on your Web page: A paragraph can be written on the web document using the <p> tag. This is a container tag, though the </p> tag is optional.

→ It uses one attribute called align that takes the value left, right or center.

• The Center tag: It places the text in the center. Sometimes it may not be possible to use align
attribute again and again along with a tag. Then it is better to use nested form of center
tag once and use other tags inside the opening and closing center tags.

• Bold, Italics and Underline: There are other tag that help in changing the style of the font.

→ <B> , </B> : used for making bold text.
→ <I> , </I> : used for making italic text.
→ <U> , </U>: used for making underlined text.